Diffusion soldering connections have been used for some time for soldering semiconductor chips to a metallization of a carrier. In this case, a metallization of a semiconductor chip is soldered to a metallization of a carrier using a solder. During the soldering process, metal from the metallizations of the semiconductor chip and of the carrier diffuses into the liquid solder and forms together with the latter after solidification one or more intermetallic phases having high strength and stability with respect to thermal cycling.
Since the diffusion process in which the metals from the metallizations of the semiconductor chip and of the carrier diffuse into the liquid solder takes up a not inconsiderable time for achieving an intermixing required for the formation of intermetallic phases, the processing times associated with the production of such soldering connections are very long. Moreover the concentration of the indiffused metals decreases with the distance from the respective metallizations of the semiconductor chip and of the carrier. This results in different stoichiometric compositions in different regions of the melt. This has the effect that after solidification the melt does not exclusively consist of intermetallic phases, but rather a considerable proportion of simple alloys which do not have a lattice structure and therefore do not constitute an intermetallic phase. Since commercial alloys have a lower strength and a lower stability with respect to thermal cycling in comparison with intermetallic phases, there is a need for an improved solution.